aboutsummaryrefslogtreecommitdiffstats
path: root/libmaple/gpio.c
blob: 5484e2186a32bb21ee64df9f1646bb042530c1f9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/******************************************************************************
 * The MIT License
 *
 * Copyright (c) 2010 Perry Hung.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *****************************************************************************/

/**
 * @brief GPIO initialization routine
 */

#include "gpio.h"
#include "rcc.h"

/*
 * GPIO devices
 */

gpio_dev gpioa = {
    .regs      = GPIOA_BASE,
    .clk_id    = RCC_GPIOA,
    .exti_port = AFIO_EXTI_PA,
};
gpio_dev* const GPIOA = &gpioa;

gpio_dev gpiob = {
    .regs      = GPIOB_BASE,
    .clk_id    = RCC_GPIOB,
    .exti_port = AFIO_EXTI_PB,
};
gpio_dev* const GPIOB = &gpiob;

gpio_dev gpioc = {
    .regs      = GPIOC_BASE,
    .clk_id    = RCC_GPIOC,
    .exti_port = AFIO_EXTI_PC,
};
gpio_dev* const GPIOC = &gpioc;

gpio_dev gpiod = {
    .regs      = GPIOD_BASE,
    .clk_id    = RCC_GPIOD,
    .exti_port = AFIO_EXTI_PD,
};
gpio_dev* const GPIOD = &gpiod;

#ifdef STM32_HIGH_DENSITY
gpio_dev gpioe = {
    .regs      = GPIOE_BASE,
    .clk_id    = RCC_GPIOE,
    .exti_port = AFIO_EXTI_PE,
};
gpio_dev* const GPIOE = &gpioe;

gpio_dev gpiof = {
    .regs      = GPIOF_BASE,
    .clk_id    = RCC_GPIOF,
    .exti_port = AFIO_EXTI_PF,
};
gpio_dev* const GPIOF = &gpiof;

gpio_dev gpiog = {
    .regs      = GPIOG_BASE,
    .clk_id    = RCC_GPIOG,
    .exti_port = AFIO_EXTI_PG,
};
gpio_dev* const GPIOG = &gpiog;
#endif

/*
 * GPIO convenience routines
 */

/**
 * Initialize a GPIO device.
 *
 * Enables the clock for and resets the given device.
 *
 * @param dev GPIO device to initialize.
 */
void gpio_init(gpio_dev *dev) {
    rcc_clk_enable(dev->clk_id);
    rcc_reset_dev(dev->clk_id);
}

/**
 * Initialize and reset all available GPIO devices.
 */
void gpio_init_all(void) {
    gpio_init(GPIOA);
    gpio_init(GPIOB);
    gpio_init(GPIOC);
    gpio_init(GPIOD);
#ifdef STM32_HIGH_DENSITY
    gpio_init(GPIOE);
    gpio_init(GPIOF);
    gpio_init(GPIOG);
#endif
}

/**
 * Set the mode of a GPIO pin.
 *
 * @param dev GPIO device.
 * @param pin Pin on the device whose mode to set, 0--15.
 * @param mode General purpose or alternate function mode to set the pin to.
 * @see gpio_pin_mode
 */
void gpio_set_mode(gpio_dev *dev, uint8 pin, gpio_pin_mode mode) {
    gpio_reg_map *regs = dev->regs;
    __io uint32 *cr = &regs->CRL + (pin >> 3);
    uint32 shift = (pin & 0x7) * 4;
    uint32 tmp = *cr;

    tmp &= ~(0xF << shift);
    tmp |= (mode == GPIO_INPUT_PU ? GPIO_INPUT_PD : mode) << shift;
    *cr = tmp;

    if (mode == GPIO_INPUT_PD) {
        regs->ODR &= ~BIT(pin);
    } else if (mode == GPIO_INPUT_PU) {
        regs->ODR |= BIT(pin);
    }
}

/*
 * AFIO
 */

/**
 * Initialize the AFIO clock, and reset the AFIO registers.
 */
void afio_init(void) {
    rcc_clk_enable(RCC_AFIO);
    rcc_reset_dev(RCC_AFIO);
}

#define AFIO_EXTI_SEL_MASK 0xF

/**
 * Select a source input for an external interrupt.
 *
 * @param exti      External interrupt.  One of: AFIO_EXTI_0,
 *                  AFIO_EXTI_1, ..., AFIO_EXTI_15.
 * @param gpio_port Port which contains pin to use as source input.
 *                  One of: AFIO_EXTI_PA, AFIO_EXTI_PB, AFIO_EXTI_PC,
 *                  AFIO_EXTI_PD, and, on high density devices,
 *                  AFIO_EXTI_PE, AFIO_EXTI_PF, AFIO_EXTI_PG.
 * @see exti_port
 */
void afio_exti_select(afio_exti_num exti, afio_exti_port gpio_port) {
    __io uint32 *exti_cr = &AFIO_BASE->EXTICR1 + exti / 4;
    uint32 shift = 4 * (exti % 4);
    uint32 cr = *exti_cr;

    cr &= ~(AFIO_EXTI_SEL_MASK << shift);
    cr |= gpio_port << shift;
    *exti_cr = cr;
}